A simple approach for producing highly efficient DNA carriers with reduced toxicity based on modified polyallylamine

Area of Science:

• Biomaterials Science
• Gene Therapy
• Nanotechnology

Background:

• Non-viral vectors are preferred for gene delivery due to safety and immunogenicity advantages over viral vectors.
• However, non-viral vectors often exhibit low transfection efficiency and high toxicity, limiting their clinical application.
• Polyallylamine (PAA), a cationic polymer, is explored as a gene delivery vector but requires modification to overcome limitations.

Purpose of the Study:

• To enhance the transfection efficiency and reduce the cytotoxicity of polyallylamine (PAA) using hydrophobic modifications.
• To investigate the effect of grafting different alkyl acrylate chains (butyl, hexyl, decyl) at varying percentages onto PAA.
• To evaluate the gene delivery performance of modified PAA vectors in Neuro2A cell lines.

Main Methods:

• Polyallylamine (PAA) with molecular weights of 15 kDa and 65 kDa was grafted with butyl, hexyl, and decyl acrylate at 10%, 30%, and 50%.
• DNA condensation ability was assessed using the ethidium bromide assay.
• Polyplexes (polymer-DNA complexes) were characterized for size, zeta potential, transfection efficiency, and cytotoxicity in Neuro2A cells.

Main Results:

• Grafting PAA decreased DNA condensation ability, but effective condensation was achieved at moderate to high carrier-to-DNA ratios.
• Polyplexes generally ranged from 150-250 nm in size, with zeta potentials mostly positive, though high grafting percentages resulted in negative potentials.
• Vectors with hexyl acrylate chains demonstrated the highest transfection activity, and grafting reduced cytotoxicity, particularly at 30% and 50% modification.
• PAA 15 kDa-based vectors showed superior transfection efficiency compared to PAA 65 kDa vectors.

Conclusions:

• Grafting polyallylamine (PAA) with hydrophobic chains, especially hexyl acrylate at high percentages onto PAA 15 kDa, significantly improves gene delivery.
• These modified PAA vectors exhibit enhanced transfection efficiency and reduced cytotoxicity, presenting a promising alternative for non-viral gene delivery.
• The study highlights the potential of tailored polymer modification for optimizing non-viral gene vector performance.